1. Field of the Invention
The invention relates to a method for conserving soil and water, and more particularly to a soil and water conservation construction by independently or jointly growing or transplanting plants at site to form a three-dimensional structure after the construction is completed, and the method is used for protecting plants on hillside lands or beautifying constructions such as a retaining wall or a dam by planting a vegetation on the constructions or decorating the constructions with the vegetation.
2. Description of the Related Art
There are various different soil and water conservation methods including a prestressed girder method, a free girder method, and a piling and grating method, etc. The prestressed girder method uses a prestressed anchor to fix and support a girder, and the hollow portion of the girder is filled with soil and planted with plants. The free girder method uses an anchor rod to fix the girder. Similar to the prestressed girder method, the hollow portion of the girder is filled with soil or soil bags for vegetations. The difference resides on that the main function of the prestressed anchor is used for preventing soil slides along the slopes, and the free girder is used for protecting the slope surface only. The piling and grating method uses bamboos and wooden piles to support the grates for filling soils and growing plants and facilitate beautifying the land with plants or trees.
Basically, these methods have the following features:
1. The surface of the construction built by these methods is planarized to simplify the complexity of construction, and the construction is built with the same structure and dimensions along the slope. Thus, the planarization is unfavorable for the soil conservation, and the slope may be eroded by rain or water and the growing effect for plants will drop. Therefore, it is necessary to have drainage to protect the constructions.
2. These methods come with a single function only. Without any special accessory method, the aforementioned soil and water conservation methods can be used for protecting slopes only and cannot be used for other purposes such as beautifying the constructions.
3. These methods require many accessory items such as the prestressed girder method requires casting the girder, building a construction framework for a higher or steeper slope to work with a moldboard of the girder, assembling the steel bars, or performing the concrete casting. In fact, the prestressed girder method also requires the same items.
4. These methods have many limitations on the slope, such as it involves a different wooden piling and a poor soil conservation effect when building the piles and grates on a steep slope, and thus greatly reducing the effect for vegetations.
5. Lots of slope finishing jobs are performed for the purposes of making the construction successful and reducing the falling rocks during or after the construction. Thus, it is necessary to remove loose soils and stones and incur a heavy workload. Furthermore, it is uneasy to remove the soils and stones.
6. Vegetation mainly fills fertile soil with seeds, and this point is affected by the vegetation concept of growing grasses evolved to growing trees and also directly related to the structure adopted by the method itself. For example, vegetations are carried out at the hollow portion of the prestressed girder by filling or stuffing which is the most appropriate method for the structure of the construction. Thus, grasses that can grow fast and have deeper roots are generally used, and trees and local prototypes are planted afterward. Therefore, the growth of grasses builds a secured foundation for the vegetation on the slope, and various plants are introduced for beautifying and remedicating the land, but such method is affected by the weather easily. Thus, the effect of vegetation cannot be controlled easily.
7. These methods cannot use transplantations for the construction. In the structure of each method, various plants have to be cultured first and then transferred to the slope for the vegetation, and such arrangement is very difficult without adopting other special methods.
There are many known soil and water conservation methods including the prestressed girder method, free girder method, and piling and grating method, etc. From their characteristics, each method produces a planarized structure that will be eroded by rain or water easily, and thus related water constructions are needed to maintain the slope and the effect of the vegetation. Before starting a construction, loose soils and stones must be removed first and thus involving tremendous workloads. The construction is also affected by the geometric shape of the slope, and thus requiring a construction framework to facilitate each construction job. Basically, each method can be used for one purpose only, and the construction by the transplanted vegetation method is very difficult.